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Hi John, love your stuff. In my daily duty as a lowly mechanic I often see tight valve clearances. The way it was explained to me was that wear occurs to the valve and seat which leads to the reduction of the valve clearance. Usually in overhead can shafts, but have seen it in some truck over head valve (rocket) set up. Out side of that, the last Pajero I checked valve clearances I found 3 spacer some breaking up. Lucky there was no damage to the can, but it would have only been a matter of time before it did. Love your work and while I admire the engineering grasp of the mechanical stuff, I do wonder at some of the locations that these wonderful designs end up in (like components too close to body parts to remove them) keep up the good work.
@@skillsrev - That is correct. All valves tighten due to wear on the valve and seat. Valve become noisy and what they call "loose" over time due to wear somewhere else on the valve train. Honda had some really bad camshafts in the 80's that would wear down increasing valve clearance, but most other manufactures wear comes from rocker arms etc. I think it's amazing that they still use rocker arms in this day and age when there are other systems that are easier to manufacture, assemble and maintain. As for your question about components too close to the body to be removed, there is a simple explanation. I worked for a major automotive company before they all disappeared a few years back. This was an area I was sometimes involved in. On production cars, engines are made and used in various models of cars. The only communication between the engine engineers and car body engineers is for assemble on the assemble line. They are both mechanical engineers, but usually two different departments, and in some cases, different locations. There is never any discussions or consideration given to the mechanic who has to service them. The fact that there is any room at all is only due to the fact it was required to install the engine.
@@gjw45 You got it, 1 engine for to many vehicle bodies certainly does the trick to make for some easy turned difficult repairs. Used to work on the old type cargos and they ran marine engines, great motor and they were fitted in a diagonal shape which was great for making a lower floor and cab. Did have some issues during some repairs but as a whole not the worst out there.
Not all overhead cam engines have rocker arms. Some engines have the cam lobe on valve design. In this case the clearance is set by shims on the cam bucket, usually not requiring adjustment. Valve adjustment is generally required when the valve and valve seat wear reducing valve clearance. Not forgetting hydraulic lifters which look after themselves. Cheers
I love how you break servicing a vehicle down to help people understand that it’s not a money grab, it’s actually what is needed to keep mechanical parts working. I also can’t understand the concept of having an expensive mechanical item that you rely heavily upon for your daily needs yet neglect proper maintenance, then complain when it fails at an inopportune time.
I am a retired aircraft mechanic. I change parts on a schedule still because I can't stand for a failure. I am still in the mindset that the vehicle will fall out of the sky if I wait until it fails to change it.
Hi John entertaining as usual. The question of valve clearances growing or shrinking is usually less to do with the slings and arrows of outrageous fortune and more to do with the valve operating arrangement. Valves that are operated by a rocker as opposed to bucket and shim have more components. As these components wear more space is opened between the components and so valve clearances grow, as does the tappet noise as now due to greater clearance the rocker is activating later and on a more aggressive area of the cam lobe. In contrast in a bucket and shim setup the cam lobe is directly above the vale and the bucket and shim are hardened. In this system usually the highest wear component is the valve seat. As the valve wears into the seat the end of valve stem moves closer to the cam. This lifts the bucket and shim assembly closer to the cam and so usually leads to the valve clearances shrinking over time. Cheers
Back in the 80s the motorcycles I owned had the valve clearance check procedure in the Owner Manual, which I did a few times. It was just expected that owners would be the ones to do it.
G'day, Yeah... My son, born in 1989, is an Auto Electrician... He told me he could prove to me that Humanity is De-evolving and becoming Stupificated, By "Progress". I "Bit"..., & asked how it was so...; And he replied by asking if I remembered the Owner's Manual of my first Car (1967 Morris -1100) ? ; which I admitted to. And he asked if I recalled that it instructed me how to Inspect & Adjust the Valve Clearances...(?) ; And again I admitted to not only Remembering..., But to having successfully Followed Those Instructions... Then he enquired if I've read the Owner's Manual of my current Fire-Chariot (2000-vintage Subaru Forester) ? Which I again admitted to having done. Then he smiled, And Said..., "And in your current Car's Owner's Manual...; It tells you to Take It To An Authorised Dealer For ALL Servicing & Maintenance...; And it WARNS You..., NOT To Drink the Battery Acid...!" And, He isn't Wrong. Quod Erat Demonstrandum. Have a good one... Stay safe, ;-p Ciao !
Agree. It is amazing how well engines hold up. Not a engineer (just learn from UTers like you), but about 20 years ago, I read a college text book from the U of Michigan on engine design. I remember being shocked when the author discussed some of the tradeoff. And even how well one oil type for an engine that can run 150-300K miles that must lub/protect the demands of the impact of a rocker arm/cam to sliding piston rings in an explosive environment to journal bearings riding on a film is amazing. Hats off to the engineers and chemist!
I paid a high service fee due to the valves in my Isuzu MUX being listed for adjustment, I know for a fact that they were not touched. I asked two mechanic mates if this was common and both said they could not remember the last time they did a valve adjustment and that all they do is a "sensory test", that is they listen to see if they can hear anything out of the ordinary. They both said they would get the sack if they actually took the time to adjust the valves during a service. One works for a Toyota dealer, the other one for a Ford/Hyundai dealer. Some of the other things they skip would also surprise many people. I now do my own servicing.
Not a slight surprise to me. It is not just dealer (I would say particularly dealership would skip things they meant to do), I believe almost everyone is doing it.
That would depend on the dealer. I used to go to one dealer (Graham Jacka Holden) that would happily do services properly. If you paid them what you were meant to for the service, they completed it by the book and without ripping anyone off. The Holden dealer in the nearby town that I moved to on the other hand, was the exact opposite and not only wouldn't complete services properly, but bent you over without the use of KY Gel for the privilege. The Ford dealer in that same town on the other hand were fantastic when it came to their service, but you definitely paid for it with them. My local Ford dealer where I am now I've also had positive experiences with regards to the BA Falcon I used to have, and same with my local Hyundai/Kia dealer's (one of the few I know of that the dealerships have a combined servicing and parts department for both Hyundai and Kia dealers which sales departments are in separate buildings) parts department who will get me parts in the same day if they haven't got what I need in stock. I've never used their servicing department but I would use them in a heartbeat. Early Toyota 22R-Es needed the tappets to be adjusted on a regular basis, but that was due to an issue with oil starvation in the top of the motor (something my parents experienced with their RT142 Corona).
Yes, I always adjusted the valve clearance on my car. But when I eventually sold my 1956 FE Holden nothing I bought since has never needed valve adjustment.
I've only owned two vehicles that had manually adjusted valve clearances, one had the Austin A+ engine & the other a PSA TU3 - both where simple enough for me to check & adjust when required.
Yup, almost every vehicle I've owned has had overhead cams operating directly onto buckets with spacers that have never needed any attention - those that haven't had just required simple lash adjustment, only needing a set of spanners and feeler gauges to adjust. Fortunately I've never owned a Pajero, or any other Bitsamissing product I guess.
Brilliant explanation. I’ve always tried to understand how these components can even begin to be reliable when they operate in a hammering blur of heat, stress and friction, modified by oil. We all take so much for granted.
My self a Diesel Mechanic on big big yellow machine components for 45 years and I get my valve clearance set by a specialist on the venerable 1HZ for two reasons, I don't have the tooling to do them myself, they are set by shims and are a pain in the arse which leads to the second reason which is I can't be F!@#ed doing them myself.
The last engine I had with adjustable valves was a slant 6 Dodge in a 1973 Dodge Tradesman van. I have never adjusted valves on any engine I had since then.
Hi John i had new Kenworth b double with cat engine, they called me from Catepilar after one million and one hundred’s kilometres to check the tappers. Respect 👌
Many years ago (1975) I had a Vauxhall Victor (1957/8) and I had the engine apart and did the rings and bearings as all 15 yearold boys should with Dad's guidance and we had the Haynes manual. Valve clearance was abot 12 thou' If I recall correctly. It ran ok so all good. Sometime later Brother got a Mk11 Cortina, and we fiddled with that but with no manual. Assuming it was similar, I set the clearance to 12, and it ran like crap. Eventually found it should be 24 and sorted it out. That was a real surprise.
If you are really lucky, valve clearances would stay close to specification if the wear in the valve train compensated for valve seat recession. Good luck with that! The valve train in Tritons from the old 3.2's onwards through the 2.5 then the 2.4 are beautifully designed and durable. With good oils and regular servicing are pretty much bulletproof. Tight clearances don't generally break rocker arms. The valves don't fully close causing leakage of combustion gases leading to burnt valves and/or seats. Clearances too loose just creates noise and reduced valve lift but the flogging of loose components probably creates more wear. The audible checks wont pick up slightly tight clearances and this is worse than being slightly loose. Feeler guages are the only true way to keep clearances correct and that requires a bit of work.
Here in motorcycle mechanic land, valve clearances generally tighten with age. Modern metallurgy and oils means the valve train doesn't shred inself like the pre 2000 engines. Tightening clearance comes from valve face/seat recession. And even then, is quite rare. All this, and 14,000 rev limits 🙂
It does happen if you keep the bike long enough and flog the crap out of it. I usually have to do my yz450 about every 25 hours as a snowbike since it pretty much lives exclusively at WOT, it's easy to tell because it won't start cold. Top end lasts about 200 hours, which considering the environment and the recommended mx intervals, is quite impressive.
72,000,000!!! LOVE this perspective! I have tried to explain revolutions to friends using my thoughts on average revvs etc. This is the perfect explanation. People honestly whinge that they have to spend money on their cars getting it serviced. Little to people realise the amount of work cars do in a year (for example)
@@dannyomeara7031 Hello :) . No, one revolution of the engine is just that, one rev. It takes 4 revolutions to complete one cycle (four stroke cycle). The engine has still completed 4 revolutions to get there. No division.
When I did my NW 2012 Pajero valve clearance , compared to the spec, two were loose, two were spot on, the rest were tight, that’s across all valves (yes the exhaust and inlet have different clearance). These adjustments are required to prevent valve train damage, but it also ran much smoother afterwards. I also inspected the chain and changed the top chain guide as these are the only real weakness of the timing system. I expect smother running will increase engine life due to lower vibrations over time. On top of this the audible check only hears loose clearances not tight ones, so just get it done!
After a 30 plus year career of engine development i am still amazed that engine's stay together as long as they do. I still think of them as just oil filled hand grenades.
So Mitsubishi 2.4 diesels suffer from valve recession problems. Last time I had that problem was with a Honda CRV with a gas conversion, never had it with a diesel but I will keep an eye on my L200.
I understand a valve service requirement based on distance, which is a good proxy for use. But I don't understand the 4 year requirement. There are other components that are serviced by km only, and some other models and yrs of diesels do injectors by km only. But newer mitsub pajero is km or yrs.
Well said John , just paid $1300 to get the valves done in my 2020 Triton at the local dealer . Yes it hurt my tight arse , but preventive maintenance is there to prevent a catastrophic failure which would cost 10x more .
What grinds my gears is when you have to tell the dealerships how to do it. With the older 1KD they are supposed to be checked every 40k with a stone cold engine. So when I get a log book done on a 40k service and they tell me to bring it in I always seem to have to remind them "shouldn't I be dropping it off the night before?". However, they generally are a pretty good design, had to get mine done at 160k, at around $1500, ouch. A lot of forum warriors out there that are happy to advise it's a waste of time.
Mitsubishi cheaped out. I remember Toyota's/Yamaha's that back in the golden age of the 90s, ran the cams directly above the valves, and had them push via buckets and shims. They typically lasted the life of the engine, never needing replaced. Stuff your rocker arms, tappets.
I owned a few Yamaha’s with “shim under bucket” valve trains. One, an FZ750, had a clearance check (no adjustment required) at 44,000km. I sold it at 128,000km and though I flogged the guts out of it, it still never needed an adjustment. Awesome engines! 😁
Hello John, Brett from MRT did some fabulous work on my Pajero Sport 6 years ago. Unfortunately Brett sold MRT just prior to Covid and the new owner sadly went broke. Cheers
hi different versions of valve clearance bolt and nut = easily adjusted and commonly out of spec shim = easy job , good at staying within spec bucket = camshafts out expensive for lotsa labour
Good info as usual.....made me think "how wear makes tighter". Came to the conclusion wear at the pivot or wear at the valve seat.... Does that sound right? The seat is hammered by the valve the same number of times. " so theres that"
It's all about preventative maintenance. If the valve clearance changes more than what is normally expected, it means that there in other underlining problems and further inspection is required. It's better to catch a fault before it turns into a major engine fail. Spend a little time & money now than a full on engine rebuild later. A no brainer in my book.
I got valve clearances checked and adjusted in the the first 60k kms of my 2011 MN Triton. Never done them since and It's done nearly 300k km now. 😂 I'm also on my original injectors. Will be giving it some attention soon. I believe, doing 100k km valve clearance intervals to be more realistic and safe, this is only based on my own experience and the few mechanics I know. It's good cream for the dealers if they can get you in for more expensive services, such doing valve clearances. But, yeah must be done if you want to keep your engine warranty. Luckily for me, I've never needed their warranty service. Oh except the stupid air bag fiasco. I'll also mention, my MN is an club cab that I use for work as a sparky, it gets driven hard! It's also done a lap of Australia, fully loaded to its max gvm, Dingopiss Creek and most of the more difficult and iconic 4wd tracks. Zero mechanical problems other than wearing shit out. They're a tough little vehicle if they're serviced.
From a engineering point of view, constant low revs is about the worst thing for the valve train with respect to lubrication, it's really hard on the oil film.
John that 10 year warranty is a service contract the dealership is holding you to ransom. I am an independent mechanic in Melbourne. I do not support any notion of having to take your car back to the dealership to ensure your warranty. If you service it according to the manufacturer guidelines with proper documentation by a qualified mechanic which is allowed. they are killing small businesses like me with all this capped price servicing which is a contract tying you to the dealership.
Not worth the hassle going to an independent mechanic while the car is under warranty. And I have and old car and the independent mechanic said “we don’t work on cars built before 2010” - so very old cars also end up with the dealership.
I recall seeing an item on TV about an old guy that delivered (junk) mail around his region in a Toyota Corolla . It was news because the car had passed 1 million km. The guy said he got it serviced every 2 weeks at $400 each service. Total rip off . The car had automatic valve adjustment and the oil most likely could go on an extended oil change interval. The travel was between towns ,not stop start deliveries.
hi So listening to valve operation tells u the valves are tight or riding = valves being burnt . Listening to valves that are to loose causing cams/rockers bashing into valves etc ie excessive wear Both of these require cylinder head removal for repair .
That same job on my 28 year old LandCruiser, is using the bucket and shim. Other things like you have to repack and adjust the front wheel bearings every 20000 km. I would not be complaining about the maintenance schedule on a new vehicle.
Well many might complain because they don't have hydraulic tappets. I wouldn't complain. But I wouldn't believe anything by anyone without seeing the real data behind it. Otherwise it is just opinion and opinions are like ar*holes - everyone has one.
My experience: 3 x Suzuki 1100 (screw adjusted finger type cam followers operating 2 valves each) Checked every 40,000 km - no change in over 150,000 km Suzuki 1250 (shim under bucket type cam followers) Checked every 40,000 km , initially every exhaust valve had the same clearance and every every inlet valve had same clearance , midway in the allowable range. No change in over 150,000 km. This is the usual experience reported on owner forums. Yamaha 850 (shim under bucket type cam followers) checked at 40,000 km - all clearances at the tight end of the range This is the usual experience reported on owner forums. - 4 adjusted to be on the safe side . Next check interval not reached yet. 1993 Mazda MX5 - automatic clearance adjusters - never checked in 400,000 km + 2017 Mazda MX5 as above and expect the same , although being GDI may need valve cleaning at some stage. My usage mode of all trips being over 100km may make that necessary.
Brilliant video so 72 million multiplied by 16 valve’s therefore over a billion times. We have come a long way from doing a 1000 mile oil change on Holden grey motors guessing tapped adjustment was every 12 months
My Ex wasn’t named Cinderalla, but she was both too tight AND too loose. Too loose in morals, too tight with my money. Naturally, I ended up blowing a valve. I really should have taken up with a Ming Mole, and forever have my paint protected.
Not all forums are the same John. There are some good ones out there that don't have a scrota icon anywhere in sight. That type of humour would not be tolerated.
Surprised to see a valve clearance that closes up with use. Whatever happened to hydraulic adjusters? You would expect it to open up slightly with a bit of camshaft/rocker wear. That must mean the valves are settling in the valve seat due to valve seat recession. Too much wear with no clearance would mean the exhaust valve would not be tightly sealed so accelerating wear and eventually a failed valve due to continuous contact with hot gases and no contact with the seat which is a vital heatsink for the exhaust valve.
The audible inspection seems a little strange, as I don't think you'll be able to hear tight clearances. I've also wondered how clearances get tight, my intuition says they should get loose as the valve train settles/wears in. Maybe it's the valves seating deeper into the head as the engine is run in that causes it? Another thing too tight clearances can do is cause valves to 'ride', which can mean shit performance and burnt exhaust valves.
As the valve goes up and down it slowly wears away the valve seat closing the clearance between valve and rocker arm as they are both mounted to the cylinder head eventually put strain back onto other valve train components like rocker arms lifters and camshaft faces
@@cptchilliring9248 Most 4 stroke motorbike heads are known for it and the wise engineers decided on Yamaha WR they should use shims instead of the adjustment screw stated in the video, I think some Ford falcons used that setup. To do the clearances you need a box full of different sized shims.
@@tolecmaviclae7349 shims are good fun, bit of maths and use of verniers always good for the brain, some also use a go no-go gauge to measure valve recession, most of my experience us in v16 18 and 20 cylinder power generation units and depending on the fuel used depended on which valve recessed quicker, always a good day doing a valve set and recession check
FWIW, I found that the valve clearances on my 2006 Honda's L13A were slightly large on both intake and exhaust (two of the intake valves and three of the exhaust valves had excessive clearance, albeit only slightly). The service manual says to check every 40,000 km or 2 years (I've only owned the car a couple of years, so have only done this once).
My 76 Civic 1200 had mechanical lifters, I adjusted them every other oil change, so about every 6,000 miles. 10K km or so. Don't most new engines have hydraulic lifters? Either way, follow the maintenance schedule that comes with your car or pay the price. 4 banger, so 8 adjustments, probably 20 minutes or less. I usually just doublechecked it was still within spec. Probably adjusted on average all of them over 100K miles I owned the car. Mostly the exhaust clearance. ( more heat and I suppose recession into the cylinder head )
The next service of my Pajero Sport will be the 48 month edition. The vehicle will have travelled ≈35,00km, not 60,000km. The representative at the dealer I usually use, told me just last week that its policy is to do the manual clearance check at 60,000km. There's so much contradictory advice in the automotive maintenance industry, lay folk like me don't know where to turn. I can tell you that it fair pisses me off.
I've often wondered about the "tight"/"loose" terminology with regard to valve adjustment. Does "tight" mean a narrow clearance, i.e. the valve will open early and close late? Or does the tightness refer to the valve itself, meaning that a "tight" valve doesn't open as much because the clearance is too great?
Tight/loose refer to the gap between the rocker and the valve. Say the right gap is 0.2mm tight is smaller gap, loose is bigger gap in extreme cases tight could mean your valve it's fully closed.
Punctuation certainly does matter. It's the difference between helping your Uncle Jack, off a horse. Or helping your uncle jack off a horse! The latter being a bit too 'Deliverance' for my tastes.
The fact that we have cars and trucks that have multiple turbos that spin at 100,000rpm and are expected to run perfectly for the life of the engine fascinates me. That's an engineering marvel.
Hi John. A question on your calculations on cam revolution vs engine revolution. Did you take into account the cam turns once per engine rotation? That would reduce your figures by a quarter, not to take anything away from the numbers they are still considerable. You invite constructive criticism and I have not scrutinised your figures intensively, just the question popped up when I watched the show in question. Feel free to shoot me down if I’m wrong. Regards Dan , I like your show and have learned a lot, Thankyou.
Pretty sure German manufacturers don't do this testing anymore - either that or they deliberately put the engines that fail the testing *just* at the right time to exceed the warranty into mass production.
Yes they do need to be checked. Every time I do a Toyota or dmax, even if it's done 60,000 since new, it needs adjusting and the drivers report improved economy. Too many surf 2lt-ii and 1kds were replaced due to loose valves. Trucks yearly get valve adjustment too. Not profiteering.
A forum helped me with my Mondeo. Didn't have overdrive and instead of needing a new automatic transmission, all I needed was a variable speed sensor. Thanks forum. Problem fixed.
The old school enthusiast and club owner forums used to be pretty good if you had an uncommon car or got into tuning and fiddling with things, needed parts or a hand doing some mechanical work. I avoid social media in general, but like any cross section of humanity you're going to get a mix of ok fellas and complete cockheads.
Jeez, adjusting valves in the 21st century? I still adjust my valves in my 55 VW pickup’s 1600 air cooled motor; and the same is done for my 66 VW Type 1’s 1200 engine. However never have done same for any other water cooled motors since I purchased my new ‘73 AMC Gremlin. Best read my encyclopedic handbooks for my 2016 Ram pickup (Ute) and 2017 Subaru Outback to see if I’m missing something relative to the valve trains in those vehicles. I know that these V6 Ram Pentastar engines have had valve train issues in their first iteration, but supposedly those issues have been resolved. Nonetheless, I’m always listening for unusual sounds emanating from its engine bay. Hopefully my respective dealers have done the necessary adjustments when these vehicles have been taken in for their required service.
Mech for 50 years (tractors/trucks). Yep, it has to be done. Yep, operating hours between adjustment is on an engine model by engine model basis, it's not one fits all. But getting a dealer to do it versus non-dealer doing it is a lucky dip. Dealer did my 3.0ltr Ranger at 40K, don't know why, didn't ask, maybe it was on the list, I don't know and don't care I was too busy at the time to think about it. A checkover by me at 60k found that 2 injectors had been fitted with debris on the gasket causing combustion leaks into the injector cavities, and, the rocker cover gasket not re-sealed at the front cam brg intersections causing oil leak into the cam belt cavity. Went back to look at the invoice, and sure enough I had been charged for a valve clearance adjustment. To do that, the 4 injectors have to be removed to get the rocker cover off. Moral of the story is- "it's not which workshop to choose, it's which spanner operator to choose". Another example- My new car first service, battery cells filled to brim, when wife got home from dealership I smelt battery acid outside, battery acid was dripping onto concrete floor, entire engine bay soaked in acid, hosed it off, rang the dealer, he said- oh not again, the labour hire guys sometimes take it literally when you tell them to top something up. Not game to let a dealer touch my new vehicles nowadays except for recalls. 3.2 Ranger wasn't game to let them change the oil even in case they blew the crank (variable vane pump issue).
Similar story as far as changing oil and not the filter too in US. It was easier with the spin on filters. You can leave a unique mark on the filter casing so it's obvious if it wasn't changed. I'm guessing you could wipe clean the cartridge housing and dust it for prints afterwards.
I enjoy watching your channel, both educational and entertaining. Mostly I agree with your comments, however... I thought the need for keeping good valve clearances was because tight clearances can prevent the valve from closing (potentially leading to burnt valve seats and poor compression) and slack clearances lead to poor gas flow. Both conditions give poor engine running. I cannot see that tight clearances add stress to the rocker arms. One rocker arm can operate two valves in a 4 valve per cylinder head, so a 16 valve head may only have 8 arms. In many double overhead camshaft engines the cams operate onto the valve stems via a bucket and shim arrangement, so no rocker arms. No mention of hydraulic cam followers either, which are supposed to be maintenance free. If the garage is charging for servicing those, suspect a con! You're the engineer, so please feel free too correct me.
A lot of engines have no rocker, the valve is under the cam lobe with hyd. lifter between. (just saying) Too tight a clearance will cause burnt valves n seats, which ain't nice. Shimming to adjust is a bit trickier than the ol' screw and locknut too. Modern engines are amazing compared to the old girls. I remember back in the day a brag was "she's done 100 thousand miles and hasn't had the head off". Thanks John
Sorry to question you but a four valve engine uses a cross head or bridge to push two valves of that one rocker arm, valve seat wear reduces your valve train clearance cam and follower wear increases it and there is the overhead cams that use that pain in the ass shim& bucket principle.
@@AutoExpertJC Yep, even Concorde, which was 62 metres long on the ground, 'stretched' 15-25cm in flight due to heat - gotta love the engineers who solved that problem!
The value gap is to allow for hear expansion. Often exhaust clearances are larger because the valve gets hotter and expand more. If the gaps disappear the valve can be help open, and that's not good.
Chat GPT-4 on "whichever" and "which ever": "Whichever" is a determiner or pronoun used to emphasize that it does not matter which one of the available options is chosen. It means "any one that" or "no matter which one." "Whichever" is more commonly used in everyday speech and writing. Examples: Whichever road you take, you'll reach the town center. You can pick whichever dessert you want from the menu. "Which ever" is a less common phrase that separates "which" and "ever" for emphasis. It can be used in similar contexts as "whichever," but it often emphasizes surprise, disbelief, or confusion. However, this usage is less standard, and "whichever" is generally preferred. Example: Which ever way you look at it, the situation is complicated. In most cases, "whichever" is the more appropriate and versatile term, while "which ever" is used more sparingly for emphasis.
Doing 2000 RPM average ( taking John's example ) { very rough maths here } Each rocker, valve etc ( everything in that line ) does 1 million cycles in under 17 hours operation. OK, let's allow the driver to have rest stops, refueling etc, so 1 million cycles a day. That is ( including the driver etc gets some days off ) about 170 million cycles per 6 months. Let's see someone spinning on the spot that many times and see if the are broken.
I don't do Facebook, but my wife sometimes reads me stuff off it while we travel, I have to ask her to stop before I cry at times, the last one being about a couple of her friends travelling in Western Qld (near Quilpie) and got a flat tyre. Didn't have a spare, surely these people are just geeing poor, dumb folks like me up, surely, especially when I head Dingo Piss Creek way, I take duos spares for each machine. There we go, got 'duos' in there. Just need to figure out the inverted two finger emoji.
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MRT sold a while back I think it’s shut now
Hi John, love your stuff. In my daily duty as a lowly mechanic I often see tight valve clearances. The way it was explained to me was that wear occurs to the valve and seat which leads to the reduction of the valve clearance. Usually in overhead can shafts, but have seen it in some truck over head valve (rocket) set up. Out side of that, the last Pajero I checked valve clearances I found 3 spacer some breaking up. Lucky there was no damage to the can, but it would have only been a matter of time before it did. Love your work and while I admire the engineering grasp of the mechanical stuff, I do wonder at some of the locations that these wonderful designs end up in (like components too close to body parts to remove them) keep up the good work.
@@skillsrev - That is correct. All valves tighten due to wear on the valve and seat. Valve become noisy and what they call "loose" over time due to wear somewhere else on the valve train. Honda had some really bad camshafts in the 80's that would wear down increasing valve clearance, but most other manufactures wear comes from rocker arms etc.
I think it's amazing that they still use rocker arms in this day and age when there are other systems that are easier to manufacture, assemble and maintain.
As for your question about components too close to the body to be removed, there is a simple explanation. I worked for a major automotive company before they all disappeared a few years back. This was an area I was sometimes involved in. On production cars, engines are made and used in various models of cars. The only communication between the engine engineers and car body engineers is for assemble on the assemble line. They are both mechanical engineers, but usually two different departments, and in some cases, different locations. There is never any discussions or consideration given to the mechanic who has to service them. The fact that there is any room at all is only due to the fact it was required to install the engine.
@@gjw45 You got it, 1 engine for to many vehicle bodies certainly does the trick to make for some easy turned difficult repairs. Used to work on the old type cargos and they ran marine engines, great motor and they were fitted in a diagonal shape which was great for making a lower floor and cab. Did have some issues during some repairs but as a whole not the worst out there.
Not all overhead cam engines have rocker arms. Some engines have the cam lobe on valve design. In this case the clearance is set by shims on the cam bucket, usually not requiring adjustment. Valve adjustment is generally required when the valve and valve seat wear reducing valve clearance. Not forgetting hydraulic lifters which look after themselves. Cheers
I love how you break servicing a vehicle down to help people understand that it’s not a money grab, it’s actually what is needed to keep mechanical parts working. I also can’t understand the concept of having an expensive mechanical item that you rely heavily upon for your daily needs yet neglect proper maintenance, then complain when it fails at an inopportune time.
It's a money grab because they don't do the work they claim to be doing
I am a retired aircraft mechanic. I change parts on a schedule still because I can't stand for a failure. I am still in the mindset that the vehicle will fall out of the sky if I wait until it fails to change it.
Hi John entertaining as usual. The question of valve clearances growing or shrinking is usually less to do with the slings and arrows of outrageous fortune and more to do with the valve operating arrangement. Valves that are operated by a rocker as opposed to bucket and shim have more components. As these components wear more space is opened between the components and so valve clearances grow, as does the tappet noise as now due to greater clearance the rocker is activating later and on a more aggressive area of the cam lobe. In contrast in a bucket and shim setup the cam lobe is directly above the vale and the bucket and shim are hardened. In this system usually the highest wear component is the valve seat. As the valve wears into the seat the end of valve stem moves closer to the cam. This lifts the bucket and shim assembly closer to the cam and so usually leads to the valve clearances shrinking over time. Cheers
I'm no mechanic and that makes sense
Back in the 80s the motorcycles I owned had the valve clearance check procedure in the Owner Manual, which I did a few times. It was just expected that owners would be the ones to do it.
G'day,
Yeah...
My son, born in 1989, is an Auto Electrician...
He told me he could prove to me that
Humanity is
De-evolving and becoming
Stupificated,
By
"Progress".
I
"Bit"..., & asked how it was so...;
And he replied by asking if I remembered the
Owner's Manual of my first Car (1967 Morris -1100) ? ; which I admitted to.
And he asked if I recalled that it instructed me how to
Inspect &
Adjust the
Valve Clearances...(?) ;
And again I admitted to not only
Remembering...,
But to having successfully
Followed
Those
Instructions...
Then he enquired if I've read the
Owner's Manual of my current
Fire-Chariot
(2000-vintage Subaru Forester) ?
Which I again admitted to having done.
Then he smiled,
And
Said...,
"And in your current Car's
Owner's
Manual...;
It tells you to
Take It To An Authorised
Dealer
For
ALL
Servicing &
Maintenance...;
And it
WARNS
You...,
NOT
To
Drink the
Battery
Acid...!"
And,
He isn't
Wrong.
Quod
Erat
Demonstrandum.
Have a good one...
Stay safe,
;-p
Ciao !
Agree. It is amazing how well engines hold up. Not a engineer (just learn from UTers like you), but about 20 years ago, I read a college text book from the U of Michigan on engine design. I remember being shocked when the author discussed some of the tradeoff. And even how well one oil type for an engine that can run 150-300K miles that must lub/protect the demands of the impact of a rocker arm/cam to sliding piston rings in an explosive environment to journal bearings riding on a film is amazing. Hats off to the engineers and chemist!
I paid a high service fee due to the valves in my Isuzu MUX being listed for adjustment, I know for a fact that they were not touched. I asked two mechanic mates if this was common and both said they could not remember the last time they did a valve adjustment and that all they do is a "sensory test", that is they listen to see if they can hear anything out of the ordinary. They both said they would get the sack if they actually took the time to adjust the valves during a service. One works for a Toyota dealer, the other one for a Ford/Hyundai dealer. Some of the other things they skip would also surprise many people. I now do my own servicing.
Yep mechanics are pushed and get rewarded to do the service as quick as possible. Quality of the service comes second
Not a slight surprise to me. It is not just dealer (I would say particularly dealership would skip things they meant to do), I believe almost everyone is doing it.
That would depend on the dealer. I used to go to one dealer (Graham Jacka Holden) that would happily do services properly. If you paid them what you were meant to for the service, they completed it by the book and without ripping anyone off. The Holden dealer in the nearby town that I moved to on the other hand, was the exact opposite and not only wouldn't complete services properly, but bent you over without the use of KY Gel for the privilege. The Ford dealer in that same town on the other hand were fantastic when it came to their service, but you definitely paid for it with them. My local Ford dealer where I am now I've also had positive experiences with regards to the BA Falcon I used to have, and same with my local Hyundai/Kia dealer's (one of the few I know of that the dealerships have a combined servicing and parts department for both Hyundai and Kia dealers which sales departments are in separate buildings) parts department who will get me parts in the same day if they haven't got what I need in stock. I've never used their servicing department but I would use them in a heartbeat.
Early Toyota 22R-Es needed the tappets to be adjusted on a regular basis, but that was due to an issue with oil starvation in the top of the motor (something my parents experienced with their RT142 Corona).
@@ayrproductions Yes mate it does, if you have one you can trust then support them.
Sensory test does nothing if the valves seats suffer from wear and the valves wear tight
Valves and valve seats wearing down causes valve lash to decrease or tighten over time.
Glad someone raised this point. There were gaps in the information being presented.
Yes, I always adjusted the valve clearance on my car. But when I eventually sold my 1956 FE Holden nothing I bought since has never needed valve adjustment.
I've only owned two vehicles that had manually adjusted valve clearances, one had the Austin A+ engine & the other a PSA TU3 - both where simple enough for me to check & adjust when required.
Yup, almost every vehicle I've owned has had overhead cams operating directly onto buckets with spacers that have never needed any attention - those that haven't had just required simple lash adjustment, only needing a set of spanners and feeler gauges to adjust. Fortunately I've never owned a Pajero, or any other Bitsamissing product I guess.
hello, Mr. Cadogan, this show was high level edutainment. Thank you from an engineering standpoint.
Brilliant explanation. I’ve always tried to understand how these components can even begin to be reliable when they operate in a hammering blur of heat, stress and friction, modified by oil. We all take so much for granted.
Physics.
My self a Diesel Mechanic on big big yellow machine components for 45 years and I get my valve clearance set by a specialist on the venerable 1HZ for two reasons, I don't have the tooling to do them myself, they are set by shims and are a pain in the arse which leads to the second reason which is I can't be F!@#ed doing them myself.
The last engine I had with adjustable valves was a slant 6 Dodge in a 1973 Dodge Tradesman van. I have never adjusted valves on any engine I had since then.
Right? What cars still have manually adjusted valve clearance? I feel like I'm in a time machine to 1955 watching this.
Hi John i had new Kenworth b double with cat engine, they called me from Catepilar after one million and one hundred’s kilometres to check the tappers. Respect 👌
Many years ago (1975) I had a Vauxhall Victor (1957/8) and I had the engine apart and did the rings and bearings as all 15 yearold boys should with Dad's guidance and we had the Haynes manual. Valve clearance was abot 12 thou' If I recall correctly. It ran ok so all good.
Sometime later Brother got a Mk11 Cortina, and we fiddled with that but with no manual. Assuming it was similar, I set the clearance to 12, and it ran like crap. Eventually found it should be 24 and sorted it out. That was a real surprise.
If you are really lucky, valve clearances would stay close to specification if the wear in the valve train compensated for valve seat recession. Good luck with that!
The valve train in Tritons from the old 3.2's onwards through the 2.5 then the 2.4 are beautifully designed and durable. With good oils and regular servicing are pretty much bulletproof. Tight clearances don't generally break rocker arms. The valves don't fully close causing leakage of combustion gases leading to burnt valves and/or seats. Clearances too loose just creates noise and reduced valve lift but the flogging of loose components probably creates more wear.
The audible checks wont pick up slightly tight clearances and this is worse than being slightly loose. Feeler guages are the only true way to keep clearances correct and that requires a bit of work.
Here in motorcycle mechanic land, valve clearances generally tighten with age. Modern metallurgy and oils means the valve train doesn't shred inself like the pre 2000 engines. Tightening clearance comes from valve face/seat recession. And even then, is quite rare. All this, and 14,000 rev limits 🙂
It does happen if you keep the bike long enough and flog the crap out of it. I usually have to do my yz450 about every 25 hours as a snowbike since it pretty much lives exclusively at WOT, it's easy to tell because it won't start cold. Top end lasts about 200 hours, which considering the environment and the recommended mx intervals, is quite impressive.
72,000,000!!! LOVE this perspective! I have tried to explain revolutions to friends using my thoughts on average revvs etc. This is the perfect explanation. People honestly whinge that they have to spend money on their cars getting it serviced. Little to people realise the amount of work cars do in a year (for example)
But the engine is a four stroke so the cam revolution is one rev per four engine ? So divide by Four -yes?
@@dannyomeara7031 Hello :) . No, one revolution of the engine is just that, one rev. It takes 4 revolutions to complete one cycle (four stroke cycle). The engine has still completed 4 revolutions to get there. No division.
When I did my NW 2012 Pajero valve clearance , compared to the spec, two were loose, two were spot on, the rest were tight, that’s across all valves (yes the exhaust and inlet have different clearance). These adjustments are required to prevent valve train damage, but it also ran much smoother afterwards. I also inspected the chain and changed the top chain guide as these are the only real weakness of the timing system. I expect smother running will increase engine life due to lower vibrations over time. On top of this the audible check only hears loose clearances not tight ones, so just get it done!
After a 30 plus year career of engine development i am still amazed that engine's stay together as long as they do. I still think of them as just oil filled hand grenades.
Just think yourself lucky that you don't have under bucket shim valve clearance adjustment . Thank you ever so much Mr Kawasaki .
So Mitsubishi 2.4 diesels suffer from valve recession problems. Last time I had that problem was with a Honda CRV with a gas conversion, never had it with a diesel but I will keep an eye on my L200.
Brilliant as always John. I loved the ending😂
I understand a valve service requirement based on distance, which is a good proxy for use. But I don't understand the 4 year requirement.
There are other components that are serviced by km only, and some other models and yrs of diesels do injectors by km only. But newer mitsub pajero is km or yrs.
Thanks!
Well said John , just paid $1300 to get the valves done in my 2020 Triton at the local dealer . Yes it hurt my tight arse , but preventive maintenance is there to prevent a catastrophic failure which would cost 10x more .
MRT closed down a while ago .
You may want to check that out.
What grinds my gears is when you have to tell the dealerships how to do it. With the older 1KD they are supposed to be checked every 40k with a stone cold engine. So when I get a log book done on a 40k service and they tell me to bring it in I always seem to have to remind them "shouldn't I be dropping it off the night before?". However, they generally are a pretty good design, had to get mine done at 160k, at around $1500, ouch. A lot of forum warriors out there that are happy to advise it's a waste of time.
Mitsubishi cheaped out. I remember Toyota's/Yamaha's that back in the golden age of the 90s, ran the cams directly above the valves, and had them push via buckets and shims. They typically lasted the life of the engine, never needing replaced. Stuff your rocker arms, tappets.
I owned a few Yamaha’s with “shim under bucket” valve trains. One, an FZ750, had a clearance check (no adjustment required) at 44,000km. I sold it at 128,000km and though I flogged the guts out of it, it still never needed an adjustment. Awesome engines! 😁
Hello John,
Brett from MRT did some fabulous work on my Pajero Sport 6 years ago.
Unfortunately Brett sold MRT just prior to Covid and the new owner sadly went broke.
Cheers
I have a new found respect for rocker-arms. Thanks John.
Love to hear your educated thoughts.
I loved it when I came from the UK 40 years ago and discovered hydraulic lifters that were set and forget.
Why aren’t they all like that.
hi different versions of valve clearance
bolt and nut = easily adjusted and commonly out of spec
shim = easy job , good at staying within spec
bucket = camshafts out expensive for lotsa labour
Good info as usual.....made me think "how wear makes tighter". Came to the conclusion wear at the pivot or wear at the valve seat.... Does that sound right? The seat is hammered by the valve the same number of times. " so theres that"
Yep, as a mechanic, usually valve clearance gets tighter. It's called valve seat recession.
It's all about preventative maintenance. If the valve clearance changes more than what is normally expected, it means that there in other underlining problems and further inspection is required. It's better to catch a fault before it turns into a major engine fail. Spend a little time & money now than a full on engine rebuild later. A no brainer in my book.
Not being a dealer trained mechanic I use a feeler gauge instead of an audible check to valve lash testing.
I got valve clearances checked and adjusted in the the first 60k kms of my 2011 MN Triton. Never done them since and It's done nearly 300k km now. 😂 I'm also on my original injectors. Will be giving it some attention soon.
I believe, doing 100k km valve clearance intervals to be more realistic and safe, this is only based on my own experience and the few mechanics I know.
It's good cream for the dealers if they can get you in for more expensive services, such doing valve clearances. But, yeah must be done if you want to keep your engine warranty. Luckily for me, I've never needed their warranty service. Oh except the stupid air bag fiasco.
I'll also mention, my MN is an club cab that I use for work as a sparky, it gets driven hard! It's also done a lap of Australia, fully loaded to its max gvm, Dingopiss Creek and most of the more difficult and iconic 4wd tracks. Zero mechanical problems other than wearing shit out. They're a tough little vehicle if they're serviced.
But what about cam over bucket over valve, I think that is a bit more involved. sometime shim replacement in some vehicles.
From a engineering point of view, constant low revs is about the worst thing for the valve train with respect to lubrication, it's really hard on the oil film.
John that 10 year warranty is a service contract the dealership is holding you to ransom. I am an independent mechanic in Melbourne. I do not support any notion of having to take your car back to the dealership to ensure your warranty. If you service it according to the manufacturer guidelines with proper documentation by a qualified mechanic which is allowed. they are killing small businesses like me with all this capped price servicing which is a contract tying you to the dealership.
Not worth the hassle going to an independent mechanic while the car is under warranty. And I have and old car and the independent mechanic said “we don’t work on cars built before 2010” - so very old cars also end up with the dealership.
@@ppal64 that’s a load of rubbish! Go to another shop, you should not need to go back to the dealer to service your vehicle
@@anakinskywalker4113 yes my other shop is the dealership.
I recall seeing an item on TV about an old guy that delivered (junk) mail around his region in a Toyota Corolla .
It was news because the car had passed 1 million km. The guy said he got it serviced every 2 weeks at $400 each service.
Total rip off . The car had automatic valve adjustment and the oil most likely could go on an extended oil change interval. The travel was between towns ,not stop start deliveries.
I watched your last video this morning. Bought the 1-2-3 blocks from your link.
I’m really enjoying the content John.
Thanks very much, Dan.
hi So listening to valve operation tells u the valves are tight or riding = valves being burnt .
Listening to valves that are to loose causing cams/rockers bashing into valves etc ie excessive wear
Both of these require cylinder head removal for repair .
That same job on my 28 year old LandCruiser, is using the bucket and shim. Other things like you have to repack and adjust the front wheel bearings every 20000 km.
I would not be complaining about the maintenance schedule on a new vehicle.
They have made them quite bulletproof.
Dmax/bt-50 still need bearing re packs every 30k but it's not discoloured till 90k
Well many might complain because they don't have hydraulic tappets. I wouldn't complain. But I wouldn't believe anything by anyone without seeing the real data behind it. Otherwise it is just opinion and opinions are like ar*holes - everyone has one.
My experience:
3 x Suzuki 1100 (screw adjusted finger type cam followers operating 2 valves each) Checked every 40,000 km - no change in over 150,000 km
Suzuki 1250 (shim under bucket type cam followers) Checked every 40,000 km , initially every exhaust valve had the same clearance and every every inlet valve had same clearance , midway in the allowable range. No change in over 150,000 km. This is the usual experience reported on owner forums.
Yamaha 850 (shim under bucket type cam followers) checked at 40,000 km - all clearances at the tight end of the range This is the usual experience reported on owner forums. - 4 adjusted to be on the safe side . Next check interval not reached yet.
1993 Mazda MX5 - automatic clearance adjusters - never checked in 400,000 km +
2017 Mazda MX5 as above and expect the same , although being GDI may need valve cleaning at some stage.
My usage mode of all trips being over 100km may make that necessary.
Brilliant video so 72 million multiplied by 16 valve’s therefore over a billion times. We have come a long way from doing a 1000 mile oil change on Holden grey motors guessing tapped adjustment was every 12 months
My Ex wasn’t named Cinderalla, but she was both too tight AND too loose. Too loose in morals, too tight with my money. Naturally, I ended up blowing a valve. I really should have taken up with a Ming Mole, and forever have my paint protected.
They have the tight/loose problem, too, only in a different orientation.
Epic, John! Thank you
I’ve seen tight valves ruin many an engine during my 45 years as an automotive technician.
You've had a big day!
Thanks for this.I didn't know the mighty triton requires the valve clearances adjusted and 1st yessssssss
Not all forums are the same John. There are some good ones out there that don't have a scrota icon anywhere in sight. That type of humour would not be tolerated.
I would love to see you on these forums, that would be very funny.
I'd kill myself. Hilarious.
Surprised to see a valve clearance that closes up with use. Whatever happened to hydraulic adjusters? You would expect it to open up slightly with a bit of camshaft/rocker wear. That must mean the valves are settling in the valve seat due to valve seat recession. Too much wear with no clearance would mean the exhaust valve would not be tightly sealed so accelerating wear and eventually a failed valve due to continuous contact with hot gases and no contact with the seat which is a vital heatsink for the exhaust valve.
The audible inspection seems a little strange, as I don't think you'll be able to hear tight clearances. I've also wondered how clearances get tight, my intuition says they should get loose as the valve train settles/wears in. Maybe it's the valves seating deeper into the head as the engine is run in that causes it?
Another thing too tight clearances can do is cause valves to 'ride', which can mean shit performance and burnt exhaust valves.
I think that intuition is spot on. 👍 Quite well documented on Honda engines.
As the valve goes up and down it slowly wears away the valve seat closing the clearance between valve and rocker arm as they are both mounted to the cylinder head eventually put strain back onto other valve train components like rocker arms lifters and camshaft faces
@@cptchilliring9248 Most 4 stroke motorbike heads are known for it and the wise engineers decided on Yamaha WR they should use shims instead of the adjustment screw stated in the video, I think some Ford falcons used that setup. To do the clearances you need a box full of different sized shims.
@@tolecmaviclae7349 shims are good fun, bit of maths and use of verniers always good for the brain, some also use a go no-go gauge to measure valve recession, most of my experience us in v16 18 and 20 cylinder power generation units and depending on the fuel used depended on which valve recessed quicker, always a good day doing a valve set and recession check
FWIW, I found that the valve clearances on my 2006 Honda's L13A were slightly large on both intake and exhaust (two of the intake valves and three of the exhaust valves had excessive clearance, albeit only slightly). The service manual says to check every 40,000 km or 2 years (I've only owned the car a couple of years, so have only done this once).
Great ending
My 76 Civic 1200 had mechanical lifters, I adjusted them every other oil change, so about every 6,000 miles. 10K km or so. Don't most new engines have hydraulic lifters? Either way, follow the maintenance schedule that comes with your car or pay the price. 4 banger, so 8 adjustments, probably 20 minutes or less. I usually just doublechecked it was still within spec. Probably adjusted on average all of them over 100K miles I owned the car. Mostly the exhaust clearance. ( more heat and I suppose recession into the cylinder head )
The next service of my Pajero Sport will be the 48 month edition. The vehicle will have travelled ≈35,00km, not 60,000km.
The representative at the dealer I usually use, told me just last week that its policy is to do the manual clearance check at 60,000km.
There's so much contradictory advice in the automotive maintenance industry, lay folk like me don't know where to turn.
I can tell you that it fair pisses me off.
I've often wondered about the "tight"/"loose" terminology with regard to valve adjustment. Does "tight" mean a narrow clearance, i.e. the valve will open early and close late? Or does the tightness refer to the valve itself, meaning that a "tight" valve doesn't open as much because the clearance is too great?
Tight/loose refer to the gap between the rocker and the valve. Say the right gap is 0.2mm tight is smaller gap, loose is bigger gap in extreme cases tight could mean your valve it's fully closed.
Is this why XK Jaguar engines do not have rocker arms, but shimmed valve adaptors?
Are there any sleeve-valve engines in cars?
Punctuation certainly does matter.
It's the difference between helping your Uncle Jack, off a horse. Or helping your uncle jack off a horse! The latter being a bit too 'Deliverance' for my tastes.
The fact that we have cars and trucks that have multiple turbos that spin at 100,000rpm and are expected to run perfectly for the life of the engine fascinates me. That's an engineering marvel.
How common is hydraulic valve clearance adjustment these days ?
I believe I have to remove fuel injectors to inspect rockers on my 2010 Colorado diesel ... is that correct?
Hi John.
A question on your calculations on cam revolution vs engine revolution.
Did you take into account the cam turns once per engine rotation? That would reduce your figures by a quarter, not to take anything away from the numbers they are still considerable.
You invite constructive criticism and I have not scrutinised your figures intensively, just the question popped up when I watched the show in question. Feel free to shoot me down if I’m wrong.
Regards Dan , I like your show and have learned a lot, Thankyou.
Pretty sure German manufacturers don't do this testing anymore - either that or they deliberately put the engines that fail the testing *just* at the right time to exceed the warranty into mass production.
I concur. Please get your valves checked as the service suggests especially on the mitsubishi engines mentioned. Early MQ Tritons were every 45k km.
Great explanation
Isothermal expansion and adibatic expansion ? Carnot cycle - PV= Mrt ?
Infinitesimally quasi-static, or real-time?
John Loves the forums 🤣🤣
Yes they do need to be checked. Every time I do a Toyota or dmax, even if it's done 60,000 since new, it needs adjusting and the drivers report improved economy. Too many surf 2lt-ii and 1kds were replaced due to loose valves. Trucks yearly get valve adjustment too. Not profiteering.
I agree - if it's in the schedule it's non-negotiable.
A forum helped me with my Mondeo. Didn't have overdrive and instead of needing a new automatic transmission, all I needed was a variable speed sensor. Thanks forum. Problem fixed.
Thanks, Mondeo forum. Was it 'MonkeyNuts333' who helped?
The old school enthusiast and club owner forums used to be pretty good if you had an uncommon car or got into tuning and fiddling with things, needed parts or a hand doing some mechanical work. I avoid social media in general, but like any cross section of humanity you're going to get a mix of ok fellas and complete cockheads.
Also if valve clearance is tight it can cause valves and seats to burn.
Its makes a difference with some modern motorcycles, BUT the service intervals are often too close together.
Jeez, adjusting valves in the 21st century? I still adjust my valves in my 55 VW pickup’s 1600 air cooled motor; and the same is done for my 66 VW Type 1’s 1200 engine. However never have done same for any other water cooled motors since I purchased my new ‘73 AMC Gremlin. Best read my encyclopedic handbooks for my 2016 Ram pickup (Ute) and 2017 Subaru Outback to see if I’m missing something relative to the valve trains in those vehicles. I know that these V6 Ram Pentastar engines have had valve train issues in their first iteration, but supposedly those issues have been resolved. Nonetheless, I’m always listening for unusual sounds emanating from its engine bay. Hopefully my respective dealers have done the necessary adjustments when these vehicles have been taken in for their required service.
Hey mate just a heads up MRT Brett Middletons shop has closed down last year
If it wasn’t for my huge value lash, I’d never know when to add more oil
Mech for 50 years (tractors/trucks). Yep, it has to be done. Yep, operating hours between adjustment is on an engine model by engine model basis, it's not one fits all. But getting a dealer to do it versus non-dealer doing it is a lucky dip. Dealer did my 3.0ltr Ranger at 40K, don't know why, didn't ask, maybe it was on the list, I don't know and don't care I was too busy at the time to think about it. A checkover by me at 60k found that 2 injectors had been fitted with debris on the gasket causing combustion leaks into the injector cavities, and, the rocker cover gasket not re-sealed at the front cam brg intersections causing oil leak into the cam belt cavity. Went back to look at the invoice, and sure enough I had been charged for a valve clearance adjustment. To do that, the 4 injectors have to be removed to get the rocker cover off. Moral of the story is- "it's not which workshop to choose, it's which spanner operator to choose". Another example- My new car first service, battery cells filled to brim, when wife got home from dealership I smelt battery acid outside, battery acid was dripping onto concrete floor, entire engine bay soaked in acid, hosed it off, rang the dealer, he said- oh not again, the labour hire guys sometimes take it literally when you tell them to top something up. Not game to let a dealer touch my new vehicles nowadays except for recalls. 3.2 Ranger wasn't game to let them change the oil even in case they blew the crank (variable vane pump issue).
Similar story as far as changing oil and not the filter too in US. It was easier with the spin on filters. You can leave a unique mark on the filter casing so it's obvious if it wasn't changed. I'm guessing you could wipe clean the cartridge housing and dust it for prints afterwards.
My 6.7 needs adjustment.
this is why I like hydraulic lifters.. They adjust for valve stem changes, and valve face changes.
I enjoy watching your channel, both educational and entertaining. Mostly I agree with your comments, however...
I thought the need for keeping good valve clearances was because tight clearances can prevent the valve from closing (potentially leading to burnt valve seats and poor compression) and slack clearances lead to poor gas flow. Both conditions give poor engine running. I cannot see that tight clearances add stress to the rocker arms.
One rocker arm can operate two valves in a 4 valve per cylinder head, so a 16 valve head may only have 8 arms.
In many double overhead camshaft engines the cams operate onto the valve stems via a bucket and shim arrangement, so no rocker arms.
No mention of hydraulic cam followers either, which are supposed to be maintenance free. If the garage is charging for servicing those, suspect a con!
You're the engineer, so please feel free too correct me.
Interesting video. Cheers 👍
Do cams spin at 2 x engine speed? Or did I not hear that correctly? Is valve seat recession not a thing anymore?
Half I think..cam gears should be twice the size of the drive gear. If im correct.
Half crankshaft speed
A lot of engines have no rocker, the valve is under the cam lobe with hyd. lifter between. (just saying) Too tight a clearance will cause burnt valves n seats, which ain't nice. Shimming to adjust is a bit trickier than the ol' screw and locknut too. Modern engines are amazing compared to the old girls. I remember back in the day a brag was "she's done 100 thousand miles and hasn't had the head off". Thanks John
Sorry to question you but a four valve engine uses a cross head or bridge to push two valves of that one rocker arm, valve seat wear reduces your valve train clearance cam and follower wear increases it and there is the overhead cams that use that pain in the ass shim& bucket principle.
Please please stop tapping paper on desk it’s very distracting , try staples 👍👍Great content 👍👍
Except for Landrover and Range Rover products. They don’t do any engine testing , they just let them fail at 60,000 kilometres, unfixable ever again .
60k is actually a good one.
Be happy it’s not a motorcycle that you have to take apart including draining the coolant and removing the cams to change the shims
Correct me if i'm wrong but MRT closed down around 12 months ago.
I'm sorry to hear that, if true. Their vids are still up - I was watching one the other day.
Thanks John, another informative video. I was told that valve clearances actually increase when hot?
Metal expands... So the valve stem lengthens.
@@AutoExpertJC Yep, even Concorde, which was 62 metres long on the ground, 'stretched' 15-25cm in flight due to heat - gotta love the engineers who solved that problem!
In a pushrod engine the valve clearance does increase with heat, especially if a alloy head and cast iron block.
The value gap is to allow for hear expansion. Often exhaust clearances are larger because the valve gets hotter and expand more. If the gaps disappear the valve can be help open, and that's not good.
Chat GPT-4 on "whichever" and "which ever":
"Whichever" is a determiner or pronoun used to emphasize that it does not matter which one of the available options is chosen. It means "any one that" or "no matter which one." "Whichever" is more commonly used in everyday speech and writing.
Examples:
Whichever road you take, you'll reach the town center.
You can pick whichever dessert you want from the menu.
"Which ever" is a less common phrase that separates "which" and "ever" for emphasis. It can be used in similar contexts as "whichever," but it often emphasizes surprise, disbelief, or confusion. However, this usage is less standard, and "whichever" is generally preferred.
Example:
Which ever way you look at it, the situation is complicated.
In most cases, "whichever" is the more appropriate and versatile term, while "which ever" is used more sparingly for emphasis.
In all my years i have never heard of clearances getting tighter with wear, sounds like they were not properly adjusted to start with. 🤔
Doing 2000 RPM average ( taking John's example ) { very rough maths here }
Each rocker, valve etc ( everything in that line ) does 1 million cycles in under 17 hours operation.
OK, let's allow the driver to have rest stops, refueling etc, so 1 million cycles a day. That is ( including the driver etc gets some days off ) about 170 million cycles per 6 months. Let's see someone spinning on the spot that many times and see if the are broken.
Hydraulic lifters negate the need to check valve clearance. I’m surprised these cars don’t use them.
Cost?
Just an observation John, have you thought about not printing your notes, and saving some paper?
Greetings from Sierra Vista, AZ
I don't do Facebook, but my wife sometimes reads me stuff off it while we travel, I have to ask her to stop before I cry at times, the last one being about a couple of her friends travelling in Western Qld (near Quilpie) and got a flat tyre. Didn't have a spare, surely these people are just geeing poor, dumb folks like me up, surely, especially when I head Dingo Piss Creek way, I take duos spares for each machine. There we go, got 'duos' in there. Just need to figure out the inverted two finger emoji.